Braking means for dual wheels



Jan. 27,1942. 3, 5, ASH

BRAKING MEANS FOR DUAL WHEELS Fil ed Oct. 12, 1959 5 Sheets-Sheet 1 IJQEEW ATTORNEYS Jan. 27, 1942. Q ASH BRAKING MEANS FOR DUAL WHEELS Filed Oct. 12, 1939 3 Sheets-Sheet 2 ATTORNEYS lu u c. s. AsH 7 2,270,919

BRAKING MEANS FOR DUAL WHEELS Filed Oct. 12, 1939 3 Sheets-Sheet 3 WQPM @w.

TTORN EYS Patented Jan. 27, 1942 I I UNITED STATES PATENT OFFICE 2,270,919 BRAKING MEANS FOR DUAL WHEELS Charles s. Ash, Milford, Mich. Application October 12, 1939, Serial No. 299,087

11 Claims.

The present invention relates to new and useful improvements in the braking of independently rotatable dual wheels such as are used for automotive road vehicles.

Objects and advantages of 'the invention will be set forth in part hereinafter and in part will be obvious herefrom, or maybe learned by practice with the invention, the same being realized and attained by means of the instrumentalities and combinations pointed out in the appended claims.

The invention consists in the novel parts, constructions, arrangements, combinations and improvements herein shown and described.

The accompanying drawings, referred to herein and constituting a part hereof, illustrate one embodiment of the invention, and together with the description, serve to explain the principles of the invention.

Of the drawings:

Figure 1 is a'vertical sectional view showing a typical and illustrative embodiment of the braking means of the present invention as applied to the dual dirigible wheels of an automotive vehicle;

Figure 2 is a fragmentary sectional view, with certain parts broken away and taken on the line 2-2 of- Figure 1;

Figure 3' is a detailed. fragmentary section taken on the line 3 -3 of Figure 2;

Figure 4 is a detailed fragmentary section taken on the line H of Figure 3;

Figure 5 is an end elevation, with certain parts broken away, of the expansible braking means of the present invention;

Figure 6 is a similar view of a modified form of expansible braking means; and

Figs. 7 and 8 are detailed sectional views taken I change'ably replaced for a non-servo brake shoe assembly in certain types of brakes for independently rotatable dual wheels. v

In the illustrative embodiment of the present invention, the braking means for the coaxial independently rotatable dual wheels comprises a pair of spaced-apart brake members which are preferably of disc-like form and are provided with braking surfaces facing each other, one of these brake members being attached to each of the wheels and the .two brake members being (or. res-1s) mounted brake members, and these cooperating brake members are preferably 50 mounted and interconnected that they exert equal pressure on the rigidly mounted brake members, and upon contact with one or the other of the rotating rigidly mounted brake members, they are further expanded so as to increase the braking effort and thereby reduce the exertion required on the part of the operator for the application of the brakes. As embodied, the cooperating expansible brake members are interconnected by means of spiral gears or oppositely'faced wedge surfaces so that their relative rotation is translated into axial expansion or contraction, and the initial relative rotation may be produced by means of a relatively small fluid pressure operated motor mounted on the brake members.

It will be understood that the foregoing general description and the following detailed description as well are exemplary and explanatory of the invention but are not restrictive thereof.

Referring now in detail to the illustrative embodiment of the invention as shown by the accompanying drawings, the invention is shown as applied to the braking of a pair of dual dirigible wheels such as are used for the steering of an automotive vehicle. At the end of the front axle I is mounted a king pin II by which the forked spindle end. I2 is pivotally supported. A wheel hub I is mounted for rotation on the spindle end l2 by means of the tapered roller bearings l6 and I1, and the outer wheel l8 provided with a pneumatic tire supporting rim I9 is bolted to the hub by means of the cap screws 20. The

' inner 'wheel provided with its tire supporting rim 26, is independently rotatably mounted on hub l5 by means of inner wheel hub 28, suitable bearings 29 and 30 being provided between the hubs. The inner wheel 25 is preferably formed with a relatively deep dish to space the rims l9 and 26 the correct distance apart, at the same time permitting the king pin H to be located between the points of contact at the tires with the road, and also providing a relatively enclosed space for the mounting of the braking mechanism for both wheels.

Spaced apart coaxial braking surfaces are rigidly attached to the inner and outer wheels, and

as embodied a brake disc having a flat braking surface II is attached to the inner end of outer wheel hub l5 by means of a flange 42 at the inner edge of the brake disc I and cap screws 43. A brake disc 46 having a flat braking surface IIv of substantially the samedimensions as surlface II is attached to the inner portion ofthe inner wheel 25 by means of the external 'fiange 48 and cap screws 49. Thus, the brake surfaces apart causing relative rotation between gears50 Cooperating expansible braking means are provided between the spaced apart brake surfaces 4| and ,41, and comprise a pair of rings 50 and substantially U-shaped in cross-section, with their open sides facing each other, the two rings being of substantially the same external diameter. The opposing faces of rings 50 and 5| are pref erably fiat and substantially parallel with each other, and are each provided with a disc or brake lining 53 firmly secured thereon, the dimensions of the brake lining corresponding generally to the dimensionsof the surfaces 4| and 41.

Means are also provided for anchoring the expansible braking means against rotation, at the same time permitting it to move axially of the wheels so that the braking pressure may be evenly distributed between the wheels and as embodied, rin 50 is formed with a pair of diametrically opposed rectangular recesses 55 which receive anchor pads 56. Pads 56 are rotatable about the king pin II but are held against rotation with the wheels by means of their cylindrically recessed faces which fit over the upper and lower fork members of spindle I2 and are retained thereon by cap screws 58 so as to form dust excluding caps for the king pin.

Means are provided for expanding the brake shoes 50 and 5| into contact with the braking surfaces 4| and 41, and for energizing the brake by the rotation of the wheels. As embodied, an internal spiral or -helical gear 60 is provided with spacing lugs 5| by which and screws 62 it is mounted within the U-shaped interior of brake shoe 50, and this gear 80 meshes with a similarly pitched external spiral or helical gear 53 ofrin shape which is fastened to the brake-shoe 5| by spacing lugs 54 and screws 65. As one of the brake shoes 50 and 5| isrotated relative to the other, the other shoe being held against rotation,

the ring gears 60 and 53 are similarly rotated and the spiral tooth formation of these gears transforms this relative rotation into axial expansion or contraction of the brake shoes 50 and 5| ,so as to engage or disengage the brake shoes with the braking surfaces 4| and 41.

The gear teeth of gears .50 and 63 may, of course, be of opposite hand on opposite sides of the vehicle, so that as the brake shoe 5| is brought into contact with the braking surface 41,.

continued rotation of the wheels in a forward direction will cause further expansion of the,brake shoes 50 and 5| to increase their braking effort. However, gears of similar hand may be employed if the brake shoe having limited rotational move- ,ment engages the inner wheel brake surface on one side of the vehicle and the outer wheel brake surface on th'e other side of the vehicle.

. Means are provided for initially expanding the brake members 50 and 5| into engagement with the brake surfaces 4| and 41, and for this purand 53 and thereby causing axial expansion of. the brake shoes in contact with the braking surfaces 4I and 41 so that the servo action of the brakes may be initiated. I

Means are also provided for retracting the brakes to their released position as soon as the pressure is relieved in the cylinder. 10, and for this purpose a spring 16 is compressed between the brackets 11 and 18 attached to the brake shoes and 5| respectively. Means are also provided f01"1l01dillg the retracted brake shoes 50 and 5| in a relatively definite position so as to prevent their rubbing against the surfaces 4| and 41. For this purpose, the spindle-fork I2 is formed with a spider having projecting arms 80 which are apertured to .receive the threaded studs 8| which are threaded into brake shoe supporting lugs 83 carried by the brake shoe 50 on its inner surface. A spring 84 is compressed between washer 85 and arm 80 and the washer is held on the stud 8| by means of cotter pin 85. A ratchet wheel 89 cooperating with the detent spring 89 permits the brake shoes 50 and 5| to be shifted axially of the brake assembly and out of contact with the surfaces 4| and 41 when the brakes are fully retracted, and this adjustment may be obtained by turning the studs 8| through their squared heads 90. A pair of tension springs 9| carried by pins secured in brake shoes 50 and 5| serves to maintain the brake shoe 5| retracted laterally against brake shoe 50 and thus out of contact with surface 41 when the brake is not in usa Figure 6 of the drawings shows a modified form of the brake shoe assembly in which registering oppositely faced wedge surfaces are circularly arranged within the brake shoes and are relatively rotatable by relative rotation of the brake shoes, these oppositely faced wedge surfaces taking the place of the inclined gear teeth of the helical or spiral gears and 53.

As embodied, one of the brake shoes comprises a rin I00 which is U-shaped in section and provided on its outer flat surface with brake linin IOI. The other brake shoe comprises a ring I03 which is also U-shaped in cross-section and of .simi1ar.external diameter, being provided on its outer flat surface with a similar brake lining I04. The inner edge of ring I03 extends considerably further than the outer edge, and the inner edge extension I05 is interiorly finished so as to bar against the outer finished surface of the inner and positioned within the annular channel, are

rigidly fixed the wedge rings I08 and I09, which may be and preferably are duplicates of each other, ring I08 being secured to brake ring I03 by pose a relatively small hydraulic cylinder 10 having a piston 1| is mounted on a bracket 12 extending from the brake shoe 5 I and piston 1| engages in a cup-shaped recess 14 in a bracket attached to the brake shoe 50. Hydraulic brake actuating fluid is supplied to the piston 10in the usual manner to conduit 15, and as the pressure is increased, the brackets 12 and 14 are moved screws IIO, while the wedge ring I09 is secured to its brake ring I00 by the screws II I. Each ofr the wedge rings comprises a circular ring of substantial thickness, and fo'rmedon one face with a uniform series of relatively sharply inclined teeth II2, these teeth being uniform throughout its circumference, and of such a shape that they will fit in to the similar teeth of the cooperating ring mounted on the other brake shoe.

Thus, the rings I08 and I09, with their teeth in engagement as shown in Figure 6, hold the brake shoes I00 and I03 only slightly spaced apart, but as the brake shoes and rings are rotated in one direction relative to each other, the brake shoes- I and I03 are expanded axially while reverse relative rotation of the shoes and rings causes axial contraction of the shoes.

The mounting and actuation of the brake shoes I00 and 803 may be identical with that of the othermodification, and the two forms of brake shoes and expanding meansare interchangeable with each other, and in fact are interchangeable with the corresponding parts shown and described in my copending application Ser. No. 263,347 filed March 22, 1939.

The invention in its broader aspects is not limited to the specific mechanisms shown and described but departures may be made therefrom within the scope of the accompanying claims without departing from the principles of the invention and without sacrificing its chief advantages.

What I claim is:

1. In a dual wheel assembly, the combination of a pair of independently rotatable dual wheels, a brake memberattached to each wheel, a brake means mounted on a stationary member and movable into braking contact with the brake members and "means rendered effective by contact of the brake means with one of the brake members while rotating for increasing the braking pressure between the brake means and both brake members,

2. In a dual wheel assembly, the combination of a pair oi. independently rotatable dual wheels, a brake member attached to each wheel and .spaced slightly from each other, cooperating brake means between the brake members and movable into raking contact with the adjacent faces of the b ake members and means rendered eflfective by contact of the brake means with one of the brake members while rotating for increasing the braking pressure between the brake means and both brake members.

3. Ina dual wheel assembly, the combination of a pair of independently rotatable dual wheels, a brake member attached to each wheel and spaced slightly from each other, an expansible brake means between the brake members and movable into braking contact with the adjacent tact of the expansible brake means with a brake faces of the brake members and means rendered effective by contact of the expansible brake means with one of the rotating brake members member while the brake members are rotating for increasing the braking pressure between the brake means and both brake members.

6. In a dual wheel assembly, the combination of a pair of independently rotatable dual wheels,

a brake member attached to each wheel, the brake members being coaxial with respect to the wheels, spaced apart from each other and rigidly secured to their respective wheels at one side of the wheel assembly, expansible brake means between the brake members movable into contact with both brake members and meansrendered effective by the contact of the expansible brakemeans with a brake member while the brake members are rotating for increasing the braking pressure between the brake means and both brake members.

7. In a' vehicle wheel brake for dual wheels, a pair ofv'expansible disc-like brake members each adapted to frictionally engage a disc-like brake member, respectively carried by the two wheels which togetherform the dual wheel, andmeans for holding said first brake members in coaxial relation and for axially expanding said first brake members, including inclined, interengaging and relatively rotatable members mounted on the first brake members.

. 8. In a vehicle'wheel brake for dual wheels, 8. pair of expansible disc-like brake members each adapted to frictionally engage a disc-like brake member, respectively carried by the two wheels which together form the dual wheel, a spiral internal gear member mounted on one of the first brake members and a meshing spiral external gear member mounted on the other of the first brake members for retaining the first brake members in coaxial relation and for axially expanding the first brake members by relative rotation.

I 9. In a vehicle wheel brake for dual wheels a pair of expansible disc-like brake members each adapted to zfrictionally engage a disc-like brake member, respectively carried by the two wheels which together form the dual wheel, a circular series of wedge members mounted on one oithe first brake members, and a similar series of oppositely facing wedge members mounted on the for increasing the-braking pressure between the brake means and both brake members. I

4. In a dual wheel assembly, the combination of a pair of independently rotatable dual wheels,

an annular disc brake member attached to each wheel, the brake members being concentric and spaced apart from each other, expansible brake means between the brake members movable into contact with both brake members and means other of the first brake members for axially expanding the first brake members by relative rotation thereof.

10. In a vehicle wheel brake for dual wheels, a pair of expansible disc-like brake members each adapted to frictionally engage a disc-like brake member, respectively carried by the two wheels which together form the dual wheel, inclined interengaging members mounted on the first brake members for axially moving the brake members by relative rotation thereof, and means carried by said first brake members for retaining the first brake members in coaxial relation.

of a pair of independently rotatable dual wheels,'

an annular disc brake member attached to each wheel, the brake members being coaxial with respect to the wheels, spacedapart from each other and mounted on one side of the wheels, expansible brake means-between the brake members movable into contact with both brake memmembers for axially moving the first brake members and means rendered efl'ective by the con-' 11. In a vehicle wheel brake for I pair of expansible disc-like 'brake members each adapted to frictionally engage a disc-like brake member, respectively carried by the two wheels which together form the dual wheel, inclined in- V terengaging members mounted on. the first brake bers by relative rotation thereof, means carried by said first brake members for retaining the first brake members in coaxial relation'and a fluid pressure operated cylinder mounted on the first brake members for relatively rotating them,

f CHARLES S. ASH.

dual wheels, a 

